212 



NATURE 



\yune 27, 1889 



were all made in the first century B.C., and were found in 

 wooden coffins, either resting on the heads or surrounding the 

 bodies of the mummies. Among them the following are of 

 special interest: — (i) A very perfect wreath composed of the 

 flowerheads of a species of Immortelle {Gnaphaliwn lufeo- 

 albziin, L. ), called by the ancients " helichrysos," and much 

 used by them in making garlands. Helichrysos wreaths are 

 mentioned by Pliny (" Hist. Nat ," xxi. 96) as having been used 

 in Egypt in Ptolemaic times, also by Theophrastus, Athenseus, 

 Cratinus, &c. (2) Portion of a curious garland made of cones 

 of papyrus pith, lychnis and rose flowers, rose petals, and scarlet 

 berries of the woody nightshade. These latter are mentioned 

 by Pliny as having been employed in garland-making by the 

 Egyptians. (3) Portion of a wreath (of Greek manufacture) made 

 of flowers of the Polyanthus Narcissus {N. Tazetta, L.). 

 Wreaths made of this flower, the "clustered Narcissus " of the 

 ancients, are often mentioned by early Greek poets. Sophocles 

 thus alludes to them : — 



6a.AA€L 5' ovpavias vtt' ^x'''** 



6 KaWijSoTpos Kar ■fi/j.ap ael 



vapKiffffos, jji.iya.Kaiv Oeaiv 



apxouov ffTeipdvccixa. — (Edipiis Coloneus, 



(4) Portion of a wreath made of the flowers of a species of 

 rose {Rosa saiicla, Richards). (5) A perfect wreath com- 

 posed of rose petals threaded by a needle on to strips of 

 twine. "Recently," writes Pliny in his history of gar- 

 lands, "the rose chaplet has been adopted, and luxury has 

 now arisen to such a pitch that rose garlands are held in no 

 esteem at all if they do not consist entirely of petals sewn 

 together with the needle "(" Hist. Nat.," xxi. 8). There are 

 also exhibited : (6) a portion of a wreath composed of twigs of 

 sweet marjoram {Oiiganwn Majorana, L. ), lychnis flowers, 

 coils of papyrus pith, and pieces of copper tinsel ; (7) a portion 

 of a wreath composed of chrysanthemum flowers and leaves, 

 purple cornflowers, and petals of the flower of a species of 

 Hibiscus ; (8) a portion of a wreath made of flowers of Matthiola 

 Librator, L., flowers of the polyanthus, narcissus, and Hibiscus 

 petals ; (9) portions of two necklaces made of flowers of the date 

 palm threaded on strips of twine; and (10) a fragment of a 

 necklace made of fruits of the date palm. (H.) Among the plant 

 remains are peach stones, dates, and date stones, walnut shells, 

 currants, pomegranates, plums, figs, chick peas, common 

 garden beans and peas, lentils, wheat, barley, and oats. These 

 are probably the remains of the ancient funeral feasts which were 

 held in the Hawara Cemetery by the relatives of the deceased 

 people who were buried there. The whole collection (of which 

 the series here exhibited is only the third part) is fully described 

 by Mr. Percy E. Newberry in Mr. Flinders Petrie's " Hawara, 

 Biahmu, and Arsinoe." 



Exhibited by Dr. H. H. Ploffert : — Photograph of lightning 

 flashes taken at Ealing, on June 6, 1889. 



UNIVERSITY AND EDUCATIONAL 

 INTELLIGENCE. 



Cambridge. — The Harkness Scholarship, for Geology and 

 Palaeontology, has been awarded to T. T. Groom, Scholar of St. 

 John's College. 



Mr. J. T. Nicolson, B.Sc.'of Edinburgh University, has been 

 appointed Demonstrator in Mechanism and Applied Mechanics. 



The Mechanical Workshops Syndicate reports that the prac- 

 tical instruction in engineering and mechanism is producing 

 excellent results in the training of engineers, but that the subject 

 suffers by the lack of a higher technical examination analogous 

 to a tripos, while the workshops do not get all the work they 

 might do, owing to the withdrawal of the University Museums' 

 work. 



An examination for Scholarships in mathematics and in chemis- 

 try and physics will be held at Peterhouse on October 15. A 

 syllabus of subjects may be obtained from the tutor. 



The local lectures in science have been larpely attended during 

 the past year ; the largest audiences being at Kettering, where 

 astronomy was the subject, and Mr. J. D. McClure the lecturer, 

 and at Lancaster, where Mr. E. A. Parkyn lectured on human 

 physiology. 



The Students' Associations have made good progress in many 

 localities, and in Surrey a student, Mr. Broderick, of Guildford, 

 was found sufficiently qualified to repeat the courses in several 

 villages with much success. 



SOCIETIES AND ACADEMIES. 



London. 



Royal Society, June 6. — "Notes on the Absorption- Spectra 

 of Oxygen and some of its Compounds." By Profs. Liveing 

 and Dewar. 



The authors give a diagram representing the absorption, both 

 in the visible and in the ultra-violet parts of the spectrum, of 

 18 metres of ordinary oxygen gas at a pressure of about 97 

 atmospheres — that is, of a mass of oxygen rather greater than is 

 contained in a vertical column of equal section of the earth's 

 atmosphere. Under the circumstances of the experiment the 

 absorptions A and B are very black, and the lines of which they 

 are composed appear much broader than in the ordinary solar 

 spectrum. The other bands are all diffuse at their edges, and, 

 so far as observed, unresolvable into lines. The complete 

 absorption of the ultra-violet rays does not extend quite so far 

 down as the limit of the solar spectrum, though it approaches 

 that limit. There is a diffuse edge of gradually diminishing 

 absorption succeeding the complete absorption, and this fact, 

 together with the rapid diminution of the extent of the complete 

 absorption with decrease of pressure, lead the authors to class this 

 absorption of the extreme rays with the diffuse bands, which, 

 according to Janssen, increase in intensity as the square of the 

 density of the gas. If that be so, it is unlikely that the limit of 

 the solar spectrum is due to the absorption of ordinary oxygen. 

 For though we may suppose interplanetary space to be pervaded 

 by materials similar to our atmosphere, yet ttiey must be in such 

 a state of tenuity tha', although they may to some extent rein- 

 force A and B, they will not add sensibly to the strength of the 

 diffuse bands. Moreover, these bands, though identical in posi- 

 tion, so far as the blue and less refrangible part of the spectrum 

 is concerned, with bands observed by Brewster and others in the 

 solar spectrum, are seen much more strongly through tubes of 

 compressed oxygen than they appear in the solar spectrum with 

 a low sun. The ultra-violet bands, of which ihe one near N 

 appears in photographs nearly as strong as the band just above 

 F, and that in the indigo, have not, so far as the authors are 

 aware, been noticed in the solar spectrum. ProV)ably they would 

 appear if photographs were taken with small dispersion when the 

 sun was low. 



As the pressure in the tube diminished, the bands rapidly 

 faded ; that in the indigo, with an oscillation-frequency or wave 

 number about 2240, was the first to disappear, then those near 

 L and O and that near E. At the same time the limit of the 

 transmitted ultra-violet light advanced from an oscillation- 

 frequency of about 3575 at 97 atmospheres, to 3710 at 50 atmo- 

 spheres and 3848 at 23 atmospheres. At 20 atmospheres the 

 three bands above C, D, and F, respectively, were still visible, 

 though faint. B remained visible until the pressure was reduced 

 to 2 atmospheres, and A could still be seen, but with difficulty, 

 when the pressure of the 18 metres of oxygen was reduced to i 

 atmosphere. 



When atmospheric air was substituted for oxygen the authors 

 found that 7 atmospheres was the limit of pressure at which they 

 could certainly distinguish A, and 18 atmospheres the limit at 

 which they could see H. It is a difficult matter to say exactly 

 when an absorption becomes invisible, but the observations on 

 air were made under the same circumstances as those on oxygen, 

 and the two sets of observations were fairly comparable. With 

 air at 75 atmospheres the three bands above C, D, and F, re- 

 spectively, could all be seen, but that near C only with difficulty. 

 The mass of oxygen and its partial pressure in the tube was in 

 this case less by about one-quarter than that which w^as required 

 to bring out the bands when oxygen alone was used. The cause 

 of this may be that the development of the diffuse bands depends 

 in some degree on the total pressure of the air, and not only 

 the partial pressure of the oxygen in it. 



The mass of oxygen which when unmixed with nitrogen madi 

 A visible would correspond to that in the tube filled with air ai 

 5 atmospheres, and that which made B visible would corre- 

 spond to air at 10 atmospheres. 1 he differences between these 

 pressures and those which are actually needed to render A and B 

 visible seem too great to be ascribed to errors of observation, and 

 seem to indicate that the addition of the nitrogen has some effect 

 on the absorptive action of the oxygen. On the other hand, 

 Egoroff found that he could still distinguish A when the thick- 

 ness of air at ordinary pressure was reduced to 80 metres 

 i {Compt. Kend., vol. ci. p. 1 144). This amount of air cor- 

 responds to rather less oxygen than the 18-metre tube would 



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II 



